There is conventionally known a joint retaining member in which among a shaft, a header that fits on one end of the shaft and a nut that fits on the other end of the shaft, at least any one of the members is formed of a shape memory alloy, so that the joint retaining member can release the mechanical binding by shape change of the shape memory alloy in accordance with heating or cooling applied to this member (for example, refer to Patent Document 1).
Also, there is conventionally known a fastening member that is formed of a shape memory alloy molded in such a shape that fastening can be released under heating, in which the fastening member is secondarily processed into a shape capable of fastening at temperatures at which it is not reverted to the memorized shape, and a microwave absorption material or infrared absorption material is coated on the surface of the fastening member or provided inside the fastening member (for example, refer to Patent Document 2).    Patent Document 1: Japanese Unexamined Patent Application, First Publication No. 2002-5124    Patent Document 2: Japanese Unexamined Patent Application, First Publication No. 2003-301815